1. Field of the Invention
The invention relates in general to a thin film transistor (TFT) substrate, a liquid crystal panel and a liquid crystal display (LCD) device using the same, and more particularly to a TFT substrate having a polymer stabilized alignment layer.
2. Description of the Related Art
The liquid crystal display (LCD) technology has made rapid progress in recent years, and factors crucial to the quality of an LCD device such as response time, view-angle and brightness are continually improved.
Referring to FIG. 1, a diagram of a TFT substrate is shown. In the pixel unit 10, the through hole connected to the TFT 4 is disposed on the common electrode 2, and is connected to the common electrode 2 by the conducting wire 1a of the second metal layer 1 (M2) along the main electrode 3a of the pixel electrode 3, such that the aperture rate is increased. However, repair becomes very difficult when breakage occurs to the second metal layer 1. The TFT 4 is positioned at a corner of the pixel unit 10, and the conducting wire 1a has to bend to pass through the pixel electrode 3. If mismatch occurs between the pixel electrode 3 and the second metal layer 1, overlapping will cause the aperture rate to decrease, further reducing the brightness of the pixel unit. To the worse, during the UV-light exposing process of forming a polymer alignment layer, the change in electrical field effect will affect the arrangement of liquid crystals and result in disclination line.
Besides, precision requirement has to be satisfied when matching the black matrix (BM) of the color filter substrate on the top layer with the TFT substrate on the bottom layer, so the design of pixel has to take the precision requirement of the manufacturing process into account. If mismatch occurs during assembly, the aperture rate is decreased and the brightness is reduced, and the arrangement of liquid crystal will be affected and disclination line will occur.